Method: mergeChangesFromDetachedToManagedInstance(ObjectChangeSet, Descriptor)

1: /**
2: * Copyright (C) 2022 Czech Technical University in Prague
3: *
4: * This program is free software: you can redistribute it and/or modify it under
5: * the terms of the GNU General Public License as published by the Free Software
6: * Foundation, either version 3 of the License, or (at your option) any
7: * later version.
8: *
9: * This program is distributed in the hope that it will be useful, but WITHOUT
10: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
11: * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
12: * details. You should have received a copy of the GNU General Public License
13: * along with this program. If not, see <http://www.gnu.org/licenses/>.
14: */
15: package cz.cvut.kbss.jopa.sessions;
16:
17: import cz.cvut.kbss.jopa.model.descriptors.Descriptor;
18: import cz.cvut.kbss.jopa.sessions.merge.DetachedValueMerger;
19: import cz.cvut.kbss.jopa.sessions.merge.ValueMerger;
20:
21: class DetachedInstanceMerger {
22:
23: private final ValueMerger valueMerger;
24:
25: DetachedInstanceMerger(UnitOfWorkImpl uow) {
26: this.valueMerger = new DetachedValueMerger(uow);
27: }
28:
29: /**
30: * Merges changes from the detached instance being merged into persistence context (clone in the specified change
31: * set) into the corresponding managed instance (original in the change set).
32: *
33: * @param changeSet Set of changes to apply to the managed instance
34: * @return Managed instance with changes merged into it
35: */
36: Object mergeChangesFromDetachedToManagedInstance(ObjectChangeSet changeSet, Descriptor descriptor) {
37:• assert changeSet != null;
38:• assert changeSet.getCloneObject() != null;
39: final Object target = changeSet.getChangedObject();
40:• assert target != null;
41:
42:• for (ChangeRecord change : changeSet.getChanges()) {
43: valueMerger.mergeValue(target, change, descriptor.getAttributeDescriptor(change.getAttribute()));
44: }
45: return target;
46: }
47: }